WATERLIME GROUP. 
4©?* 
JEurypterus microplithalmns (n. s.). 
Plate LXXX A. Fig. 7. 
Carapace semioval, straight behind, more than two-thirds as long as wide; 
outline regularly curved. Eyes small, oval, placed much within the 
margins : distance between the eyes scarcely greater than between 
the eye and the outer margin of the carapace. First joint of the thorax 
narrow. 
Fig. 7. The carapace, natural size, preserving a part of the first joint of the thorax. 
Geological position and locality. In the tentaculite limestone, associated with 
Spirifer plicatus; from a loose fragment near Cazenovia. The associate fossil is 
clearly determinate of the geological position of this specimen. 
Eurypteras lacustris. 
Plate LXXXI. Fig. 1 - 11 \ Plate LXXXI A. Fig. 1; Plate LXXXI B. 
Fig. 1 - 5 ; and Plate LXXXIII B. Fig. 3. 
Eurypterus lacustris : IIarlax , Trans. Geol. Soc. Pennsylvania, Vol. i, pa. 98, pi. v : 1834. 
— — : Idem, Med. and Pliys. Researches, p. 297. 
— — : Hibbert, Trans, of the Royal Society of Edinburgh, Vol. xiii, pi. xii. 
E. remipes : Rcemer, Hunker und Von Meyer, Palseontographica, Vol.i, p. 18. 
— — : Pictet, Traite de Paleontologie, Tome ii, pa. 29, pi. xlvi, f. 14 : 1853. 
— — : Bronn et Rcemer, Lethea, 3d edition, 1854, vol. ii, pa. 6G6, ph ix 3 , f. 1. 
Not E. remipes of Herat. 
‘Not E. lacustris, Salter, Quart. Journ. Geol. Soc. London, Vol. xv, p. 235 : 1859. 
Carapace broad, somewhat straight in front and upon the sides, about 
two-thirds as long as -wide. Eyes depressed, reniform or subelliptico- 
reniform, concentrically striated. Body robust, ovato-lanceolate : tho¬ 
racic portion a little wider than the carapace, and perceptibly narrowing 
at the fifth and sixth articulations; below which, at the commencement 
of the abdominal portion of the body, there is a marked contraction. 
The first seven joints from the head are of nearly equal length and 
extremely transverse, being seven or eight times as wide as long : the 
posterior articulations are subquadrate, and the one preceding the tail- 
joint is longer than wide. The tail-joint is prolonged into a strong 
triangular spine, which is somewhat obtuse at the extremity, and the 
angles finely serrate. 
